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Biomedical subjects

W T Boyce

Publications and source records attributed to W T Boyce.

At least 37 records · Page 2Linked to original sources
PubMed1990

Life events, social support, and cardiovascular reactivity in adolescence.

Physiologic responses to environmental stress show striking interindividual differences, beginning early in life. Whereas cardiovascular reactivity (CVR) to stress has been linked to short- and long-term changes in health, little previous work has addressed reactivity in children, and no past studies have investigated the relationship of reactivity to psychosocial factors, such as stressful life events (LE) and social support (SS). We therefore studied cardiovascular response to psychologically and physically stressful laboratory tasks in 25 adolescent boys. The degree of individual CVR was examined cross-sectionally in relationship to LE, SS, and "sense of permanence" (SP), a construct reflecting the stability or continuity in the child's life experience. Heart rate reactivity (HRR) and mean arterial pressure reactivity (BPR) were bimodally distributed, with a subpopulation of approximately 20% of subjects demonstrating an exaggerated cardiovascular response. SP was related to BPR at a borderline level of significance (R = 0.33, p less than 0.10), whereas SS was unrelated to either reactivity variable. Unexpectedly, LE was strongly and inversely related to both HRR and BPR (R = -0.40 and -0.47, respectively, p less than 0.05). Subjects reporting low numbers of previous stressful life events had the highest level of cardiovascular reactivity. Possible explanations for this finding included (1) the development of a hyperdynamic response as a consequence of avoiding or denying stressful experience, (2) an effect of exaggerated CVR on cognition and the reporting of stressful events, or, most plausibly, (3) an 'inoculation effect,' in which previous LE facilitate the development of effective coping strategies, thereby diminishing responses to stressful laboratory tasks.

Adolescent↗
PubMed1989

Health status of children in self-care.

Are children in self-care more obese, do they miss more school days, and do they make more visits to the school health office than children not in self-care? We undertook a cross-sectional survey of students in ten public elementary schools in Tucson over a two-year period in an attempt to answer these questions. The sample included 503 fifth-grade students, 137 in self-care and 366 not in self-care. Demographic information and data on school absences were obtained from school records. Physical examinations were performed at school. Obesity was assessed using the body mass index calculation, in which body mass index = (body weight in kilograms)/(height in meters). Every visit to the school health office during the 1985-1986 and 1986-1987 school years was recorded for each child. There were no differences in age between those in the self-care and adult-care groups. Boys were more likely to be in self-care, as were non-Hispanic children. There were no differences in weight, body mass index, school days missed, or visits to the school health office between children in self-care and those in adult care. Our findings suggest that, by the criteria used in this study, 11-year-old children in self-care do not suffer more ill health than their counterparts in adult care.

Absenteeism↗
PubMed1989

Recurrent injuries in schoolchildren.

Past work identifying "accident-prone" children with disproportionate rates of injury has been based on clinical data gathered in office, clinic, or emergency department settings. To avoid the biases inherent in such designs, we studied recurrent injuries in a school district population, utilizing a prospective surveillance system to identify injuries meeting standardized criteria. During three school years we observed 54,874 students, ranging in age from 6 to 18 years, for recurrent injuries, which were defined as those occurring in a year in which two or more injuries were reported for the child. Five hundred seventy-three recurrently injured children (1% of the school district population) sustained 1405 injuries (17% of the overall injury experience), a proportion significantly but only slightly greater than that expected on the basis of chance alone (14%). Most recurrently injured children were injured in only a single year, with only 15 children sustaining injuries in all three study years. Age, sex, and type of school were significant correlates of recurrent injury rates, with junior high school students, boys, and students attending schools with alternative educational programs having the highest rates of injury recurrence. The findings indicate that (1) a small group of schoolchildren sustain a disproportionate share of the overall injury experience, (2) the majority of recurrently injured children experience only transient periods of enhanced injury risk, and (3) preventive strategies may benefit from investigation of developmental and social environmental factors that alter such risk.

Adolescent↗
PubMed1989

Sociocultural factors in puerperal infectious morbidity among Navajo women.

From 1980 to 1982, a sample of 968 pregnant Navajo women in New Mexico was enrolled in a prospective study of biologic and sociocultural factors in puerperal infectious morbidity. Past studies have independently implicated both genital infection and psychosocial stressors in perinatal complications, but, to the authors' knowledge, no previous work has concurrently investigated the interactive effects of genital pathogens and psychosocial processes. Endocervical cultures for Mycoplasma hominis and Chlamydia trachomatis were obtained during prenatal visits, and structured interviews were conducted assessing social support and the degree of cultural traditionality, in this context a proxy measure of acculturative stress. The incidences of postpartum fever, endometritis, and premature rupture of membranes were significantly associated with the concurrence of two factors: the presence of genital tract M. hominis and a highly traditional cultural orientation. When demographic and conventional obstetric risk factors were controlled for, women with both M. hominis and high traditionality experienced infectious complications at a rate twice that of women with either factor alone. Among the plausible explanations for this result is the possibility that acculturative stress undermines physiologic resistance to infectious genital tract disease.

Adolescent↗
PubMed1989

Protein malnutrition in elderly Navajo patients.

In an examination of Navajo elderly inpatients and outpatients, high rates of protein undernutrition (despite normal caloric stores) were found to be prevalent. The protein malnutrition was present in each of several measures used, covering structural as well as visceral protein. It was more common in males, inpatients, and the aged elderly, but excess rates of undernutrition were found in all groups examined. These rates were higher than those in any comparable group reported to date. With multiple regression analysis, length of stay in the hospital is shown to be related to this undernutrition among inpatients studied.

Acute Disease↗
PubMed1988

The taxonomy of social support: an ethnographic analysis among adolescent mothers.

Current approaches to assessing the health-related functions of social support are based on a theoretical frame of reference regarding the taxonomic structure of social networks. Nearly all previous work addresses the issue of social network taxonomies from an etic (i.e. objective, outside) rather than emic (i.e. subjective) perspective. Because of this, we intensively studied 5 unmarried adolescent mothers over the year following the delivery of their firstborn infants, utilizing ethnographic methods to elicit detailed portrayals of their personal, subjective taxonomies of social network support. Ranked in order of successful adaptation to parenthood, the young women with the best outcomes displayed a richer, more differentiated view of their social networks' taxonomic structure and regarded individual network members as more diverse in their capacity to provide broad, multi-faceted support. A common element among all subjects was the tendency to discriminate among categories of network members according to the stability and continuity perceived in individual relationships.

Adolescent↗
PubMed1988

Injuries, absences, and visits to the nurse among children in alternative schools.

Previous research suggests ecological and programmatic characteristics of schools may influence the health and health behavior of schoolchildren. In particular, schools with alternative educational programs, such as "magnet" curricula and extended school hours, have been found to have a higher incidence of student injuries. To examine further the health correlates of alternative educational programs, the authors studied injuries, health office visits, and school absences of 983 elementary schoolchildren during the 1983-1984 academic year. The study population comprised students attending three elementary schools-two with magnet programs and one with a regular primary curriculum. All three had an option for extended school hours. The frequency of school absences was related significantly to school hours, with fewer absences found in schools with extended hours (p less than .01). Enrollment in a magnet school was associated positively and significantly with rates of both health office visits and injuries, even after adjustment for the effects of age, gender, and extended school hours (p less than .001). Finally, an interaction effect was identified in which children enrolled in both a magnet curriculum and an extended day program had substantially higher rates of health office visits than did children enrolled in either program alone (p less than .001). These findings confirm a disproportionate use of school health services for injuries and other health concerns among students attending alternative educational programs. Possible explanations include differences in student characteristics, adult supervision, or the family lifestyles of children in alternative schools.

Absenteeism↗
PubMed1987

Low birth weight, prematurity, and postpartum endometritis. Association with prenatal cervical Mycoplasma hominis and Chlamydia trachomatis infections.

We studied associations of Mycoplasma hominis, Ureaplasma urealyticum, and Chlamydia trachomatis genital infections with pregnancy outcomes, controlling by logistic and multiple linear regression for known risk factors and for the presence of the other two infections. A sample of 1204 Navajo women enrolling for prenatal care had endocervical C trachomatis, M hominis, and U urealyticum cultures and serum samples taken at enrollment and when possible after 30 weeks. Low birth weight (less than 2500 g) was associated with M hominis infection among women with a history of spontaneous abortion. Mycoplasma hominis infection was also associated with postpartum endometritis, but only among women undergoing a cesarean section (odds ratio, 4.7; 95% confidence intervals, 1.22 to 18.3). Although women with recent C trachomatis infection (IgM titer greater than 1:32 on either sample or IgG seroconversion) were at greater risk of low birth weight (19% [3/16]) than women with chronic infection (4.5% [6/133]; relative risk, 4.2), this subgroup at risk was small (11% of women with classifiable C trachomatis infection). Mycoplasma hominis and C trachomatis infections may be important preventable causes of adverse pregnancy outcomes in identifiable subgroups of women.

Cervix Uteri↗
PubMed1987

Clinical prediction of cervical spine injuries in children. Radiographic abnormalities.

During the seven-year period from 1976 through 1982, 2133 cervical spine radiographs were obtained for children less than 18 years of age at two hospitals in Tucson. Twenty-five children (1.2%) had x-ray evidence of a cervical spine injury, with a male to female ratio of 4:1. Vehicular accidents accounted for 36% of cervical spine radiographic abnormalities, and sports or playground accidents accounted for an additional 36%. In an attempt to find clinical predictors that might identify x-ray abnormalities, we reviewed the medical records of these 25 children with abnormalities and 713 randomly selected children without x-ray evidence of cervical spine injuries for the following: method of injury, presenting complaints, physical examination findings, therapy, and complications. No single clinical predictor had a sensitivity of 100% when considered in isolation, but clinical assessment consisting of EITHER a complaint of neck pain OR involvement in a vehicular accident with head trauma would have correctly identified all 25 cases of cervical spine injury. If this information had been used prospectively, the number of cervical spine radiographs ordered would have been reduced by 32%. We conclude that the use of this clinical "marker" would have positively identified all children with cervical spine injuries and would have reduced by one third the cost and radiation exposure associated with cervical spine radiographs. Because of the serious consequences of missing a cervical spine injury, we suggest that other studies confirm these results before this information is accepted as a recommendation.

Accidents, Traffic↗
PubMed1987

Circumcision and informed consent. Is more information always better?

This study observes that physicians routinely inform parents about a small minority of the medical complications and risks associated with elective circumcisions. When selecting which medical complications to mention to parents, physicians appeared to use a policy based on their subjective assessment of the frequency and seriousness of the complications' occurrence. Subsequent analyses revealed that the physicians' probability estimates were biased and their seriousness assessments were consistently less than those expressed by mothers of newborn sons. Replacing the physicians' policy of partial disclosure with a comprehensive disclosure of "unbiased" information of possible risks and complications had no effect on the mothers' decisions to have their sons circumcised but did generate numerous influences on the mothers' attitudes. Among the effects observed in mothers were a reduction in their confidence in the appropriateness of their decision and a dissatisfaction with their physician's behavior. The implications of these findings to informed consent are discussed, and a greater flexibility in providing informed consent is advocated.

Adult↗
PubMed1986

Acute Chlamydia trachomatis respiratory infection in childhood. Serologic evidence.

Serum samples from 184 infants and children whose blood was drawn during a clinic visit were tested for antibody to Chlamydia trachomatis, Epstein-Barr virus, and cytomegalovirus. Lifetime illness history was obtained from clinic records. Fifteen percent had anti-C trachomatis IgM antibody. Anti-C trachomatis IgM without IgG was significantly associated with upper respiratory tract syndromes within the 14 days prior to phlebotomy in 6- to 10-year-old patients. This association was not due to polyclonal activation from Epstein-Barr virus infection. A definitive study of chlamydial illness in children rather than infants appears to be indicated.

Acute Disease↗
PubMed1986

Social and cultural factors in pregnancy complications among Navajo women.

A population of 968 pregnant Navajo women was followed in a prospective study conducted from 1980 to 1983 at the Indian Health Service Hospitals in Gallup and Crownpoint, New Mexico. The purpose of the study was to examine social and cultural influences on obstetric and neonatal complications. The extent of traditional cultural practices and the availability of social support were ascertained in structured interviews completed during each woman's first prenatal visit. In a subsample of women, the occurrence of stressful life events was also measured during a final prenatal visit in the third trimester of pregnancy. Controlling for a variety of conventional risk factors and other potential confounders, traditional women sustained complications at a rate greater than twice that of the least traditional, most acculturated women (approximate relative risk = 2.1; p = 0.001). Social support and life events were modestly associated with maternal complications (approximate relative risk = 0.7, 0.8, respectively; p = 0.07), with poorer outcomes found among those with low social support and low numbers of life events. It is proposed that the relationship of maternal complications to all three sociocultural variables--traditionality, social support, and life events--may reflect the influences of social isolation on the course and outcomes of pregnancy.

Adolescent↗
PubMed1985

Illnesses in infants born to women with Chlamydia trachomatis infection. A prospective study.

Chlamydia trachomatis is known to cause infant pneumonitis and conjunctivitis and is a suspected cause of otitis media and gastroenteritis. To identify infections associated with exposure to C trachomatis, infant illnesses were studied through a "blinded" review of medical records of 244 infants born to women cultured antenatally for cervical C trachomatis, 25% of whom had C trachomatis-positive cultures. Compared with unexposed infants, infants exposed to C trachomatis had twice the rate of both pneumonitis and recurrent otitis media in the first six months. Infants who were exposed to C trachomatis and who had pneumonitis had higher subsequent rates of gastroenteritis than either unexposed infants or exposed infants without pneumonitis. These results suggest that appreciable outpatient infant morbidity may be associated with maternal infection with C trachomatis, and that it may either cause or promote the occurrence of early, recurrent otitis media and gastroenteritis.

Bronchitis↗
PubMed1985

Phytophotodermatitis simulating child abuse.

We explored the history in two children who had bizarre, hyperpigmented skin lesions suggestive of child abuse. A final diagnosis of phytophotodermatitis was established. The lesions resulted from inadvertent application of squeezed lime juice to the children's skin by their parents during the routine preparation of drinks, followed by sun exposure, which activated the applied plant psoralens (furocoumarins). Phytophotodermatitis can be induced by a number of plants, and, when unrecognized, may lead to inappropriate investigation of child abuse.

Child Abuse↗
PubMed1985

Permanence and change: psychosocial factors in the outcome of adolescent pregnancy.

Past work suggests that stressful life changes and the availability of social support exert opposing effects on the health of adolescent mothers and their infants. We have developed a theoretical perspective in which the effects of both stressful and protective social factors are viewed as acting on health through their capacity to either undermine or sustain an individual's sense of permanence and continuity in life experience. To examine this hypothesis, a population of 89 unmarried, pregnant adolescents were studied to ascertain psychosocial influences on maternal and infant health outcomes. This paper reports a cross-sectional analysis of perinatal complications and psychological well-being as they relate to a variety of psychosocial variables, including stressful life events, social network support and a questionnaire measure of the sense of permanence. Multivariate analyses indicate that while life events and social support had effects in the expected directions, the sense of permanence constituted an important, additional factor in the effects of social experience on pregnancy outcomes.

Adaptation, Psychological↗
PubMed1985

Infection with Chlamydia trachomatis immunotype J associated with trachoma in children in an area previously endemic for trachoma.

Chlamydia trachomatis immunotype J was isolated from the eye of a five-year-old Navajo child with trachoma. This is the first such isolate from a patient in an area previously endemic for trachoma. Chlamydial infection of the genitals among the Navajo Indians is common, and we have isolated immunotype J from the genital tract of women in this area. This most recent case points to the occurrence of "genital" trachoma. This occurrence adds evidence to the assertion that trachoma may be caused by the "genital" immunotypes of C. trachomatis. Therefore, the traditional distinction between ocular and genital strains may be artifactual.

Antibodies, Monoclonal↗
PubMed1984

Playground equipment injuries in a large, urban school district.

We studied the epidemiologic features of playground equipment-related injuries occurring in a large, urban school district over a two-year period. Nurses in each of the district's 68 elementary schools completed self-coded reporting forms on all injuries meeting standardized criteria. A total of 511 equipment-related injuries were reported, an incidence of 8.9 injuries per 1,000 student-years. One-fourth of the injuries were severe, and climbing equipment was disproportionately represented among playground equipment associated with injuries. Extreme variability was found among school-specific rates of equipment injury, with schools at the two extremes separated by as much as a 40-fold difference in incidence. Two school characteristics--smaller student enrollments and the presence of alternative educational programs--were significantly associated with higher equipment-related injury rates.

Arizona↗